Louver damper



Oct. 12, 1943; H. BARNETT 2,331,758

LOUVRE DAMPER Filed on. A4, 195s 2 sheets-sheet 1 1NVENT0R ATTORNEY.

Oct. 12,1943. H. BARNr-:T'r 2,331,758

LOUVRE DAMPER Filed oct. 4, 1939 2 sheets-sheet 2 ATTORNEY.

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Patented Oct. 12, 1943 LoUvER DAMPER Harry Barnett, Chicago, Ill., assgnor to The Powers Regulator Company, Chicago, Ill., a corporation of Illinois Application October 4, 1939, Serial No. 297,854

6 Claims.- (Cl. 98-110) My invention relates to louver dampersI and particularly to novel means for operating'` the multiple, cooperating blades of such dampers.

It is desirable, in dampers of the class described, to provide means whereby the adjacent edges of the damper'blades shall overlapwhen in closed position. However, in the type of construction in which the adjacent blades swing in reverse directions, whereby the air passing between the blades is not compelled to change its direction, difculty has been experienced in providing means for causing initial movement of the two blades at different rates of speed. The result has been 'accomplished in different manners in the Young Patent No. 2,040,893 and the Otto Patent No. 2,142,616. The present construction represents a simplied arrangement by which the desired result is accomplished.

The invention will be more readily understood by reference to the accompanying drawings, in which,

Fig. 1 is a side view, partly in section, of a louver damper and its operating means arranged in accordance with my invention, said gure being taken substantially in the plane as indicated by line I-I of Figure 2;

Fig. 2 is a fragmentary elevation of the strueture illustrated in Figure l, looking toward the left as viewed in said ligure;

vFigs. 3, 4 and 5 are partlydiagrammatic illustrations of the link movement as the result of which the desired action 'is secured.

In the drawings it willbe seen that I provide a rectangular frame I within which is mounted on suitable pivot pins the damperblades II, I2, A damper motor is indicated at I having an operating arm IS pivoted to link I'I, said link being pivoted to an ear xed to the damper blade I3. It will be noted that the blades II-I3 and YI2Ill are connected by links I8, I9 respectively in order that the blades may operate in unison. However, in order to insure that on the opening movement the edges of the blades I3-Il shall move at a greater angular velocity than the edges of the blades I4-I2 with which they respectively mate, I provide the link mechanism comprising a rocker lever 20, said lever being pivoted adjacent 'the center thereof and being mounted for rotation on a pin 2| carried on a bracket secured to `the frame, the two ends or arms of the` rocker being slightly offset relative to a line parallel to the blades, and the distance from pin 2| to blade I3, in the embodiment shown, is substantially onefourth (1/4) the length of rocker 20. Additionally, the upper arm of the rocker is angularly disposed length to the arms of the rocker 20.

with respect to a line extending upwardly from the lower arm (as shown in the dotted line) in a direction away from the blades. In other words, it may be said that lever 20 comprises two arms, one arm being disposed at an angle of 180 with respect to the other arm, the angle being measured intermediate the lever and the blades I3 and I4. The arms of the rocker 20 are of substantially the same length, and one end of the rocker is connected by a link 22 to attaching ears 23 on the upper side of the blade I3, i. e. on the side of the axis of blade I3 removed from blade I4 while the other end of the rocker is connected by a link 24 to similar ears 25 provided at the center ofthe blade I4 and extending perpendicular to blade I4. Links 122 and 24 are substantially equal in The ears 23 are as short as possible, yet are of suilicient size in order to provide an adequate and'accessible connection for link 22,but the distance of the connection between ear 23 and link 22 from the pivot point of blade I3 is substantially equal to the length of the ear 25 from the pivot point of blade I4 to the pivot point between ears 25 and lever 24.

Because of the offset or angular construction of the rocker 20 and the disposition of the links and rocker, outward swinging motion imparted to the upper edge of the blade I4 will be slower at the beginning of the opening movement than the corresponding motion of the lower edge of the blade I3. This will be true both o-n the opening andclosing movements Aand will prevent interference `between the overlapped blades. This is best explained in connection with Figs. 3, l and 5.

In Fig. 3 which shows the damper blades or louvers in fully closed position, the angle a is smaller than angle b; both` angles are obtuse and angle a is nearer to than angle b. Upon initiation of movement of the louver I3 by movement of link Il (Figure 1), the pivot point between link 22 'and ears 23 rotates clockwise on a circle about the pivot of blade I3. The rocker 20 rotates about its pivot 2l with a constant angular velocity so that the pivots between link 22 and the rocker and link 24 and the rocker move with a constant velocity. However, the pivot between arm 25 and link 24 which is substantially the same distance from the pivot of blade I4 rov-i tates counterclockwise about a circle, the center of whichl is the pivot of blade I4. As the upper end of rocker 20 moves clockwise, the pivotof link'22 and ears 23 moves, and as the lowerend of rocker 20 moves, the pivotof link 24 and arm 25 moves, but due to the disposition of the linkage position (Figure 4), the speed of the pivot between` link 24 and arm 25 approaches that of the pivot between link 22 and ears 23. In Figure 4 the at a point on the opposite side of the pivot from the pivot of the lever, means perpendicularly and rigidly connected to said second blade at the center thereof, and a link pivoted to said means and to the other arm of said lever.

3. In a louver damper construction, the combination of a pair of blades pivoted at the respective centers thereof, the edge of' one blade overblades are shown `in substantially half open posi- Y tions wherein angle d and angle b are substan tially the same as angle c. g

Beyond this point the speed of the pivot between link 24 and arm 25 exceeds that of the pivot between link 22 and ears 23, and just prior to full open position of the blades, angle a is less than angle b. In the full open position bothblades are parallel as shown in Figure 5.

It may thus be said that in eiect there 'are provided two four-bar linkages, one comprising link 22, the upper part of rocker V26, the ixed frame between pivot 2| and the pivot of blade I3, and the effective distance as shown byY dotted lines in Figures 3, 4 and', between the pivot of blade I3 and the pivot between ears 23 and link 2.2. The second four-bar linkage comprises the lower part of rocker 2B, the xed frame between pivot 2| and the pivot of blade I4, arm 25 and link 24. The'rst linkage is arranged so that, taken in the position shown in Figure 3, a constant angular velocity at 2| causes a greater angular velocity of the louver I3 about its pivot than the louver I4 about its pivot, Ydue to the fact that as the linkages have a common pivot 2| the link 22 initially moves faster than link 24, because of the disposition as above described.`

Of course reverse movement o Ithe linkages from the position shown in Figure to that shown in Figure 3 causes a` reverse operation of the parts.

, While the operation is apparent as above described, it may be said that la thrust in the direction of the arroW--Fig. l-will cause rotation of the blade I3 which rotation is transmitted through the link 22 to the rocker 2|) and vthence lapping-the adjacent edge of the other blade when said blades are in closed position, a lever pivoted adjacent the center thereof at a point interr-nediate the pivots of said blades, the arms of said lever being of substantially the same length, a link of substantially the same length as one of arms pivoted to one of said arms and to one of said blades at a point on the opposite side of 7the pivot from the pivot of said lever, means perpendicularly `and rigidly connected to said second blade at the center thereof, the effective length of said means being substantially equal to the distancefrom the pivot of said first namedr blade to the pivot between said link and said Vrst named blade, and a link of substantially the same length as the length of said first named link pivoted to` said means and te the other arm of said lever.

4. In a louver damper construction, the. combination of a pair of blades -pivoted at the respective centers thereof,` the edge of one blade overlapping the adjacent edge ofthe other blade when said blades are in closed position, a member pivoted adjacent the center thereof, a link pivoted to one arm of said pivoted member and to one of said blades-'at a point on the opposite side of the pivot from the pivot of the pivoted member, means rigid with the second blade and connected at the center of said second blade, and a link pivoted to said means and to the other arm of said through the link 24 to the attaching bracket 25.

The movement thus transmitted to blades I3--I4 is transmitted to blades I I|2 bythe links |8-|9.

I claim:

1. In a louver damper construction, the' com'` bination of a pair of blades pivoted at the respective centers thereof, the edge of one blade overlapping the adjacent edge of the other vblade when said blades are in closed position, a lever pivoted adjacent the center thereof at a point intermediate the pivots of said blades, a link pivoted to one arm of said lever and toV one of said blades at a point on the opposite side of the pivot from the pivot of the lever, means rigid with the second blade and connected at the center 'appropriate v pivoted member.

5. In a louver damper construction, the combination of a pair of pivoted louver blades, the

edge of oneblade overlapping the adjacent edge of the other blade when said blades are in closed position, a lever pivoted intermediate the ends thereof and intermediate the pivots of said blades, a link pivoted to one arm of said lever and pivoted to one of said blades at a point spaced from the pivot of said blade and on the side of the pivot of said blade opposite to that on which said lever is pivoted, a member perpendicular to the other blade and rigidly connected thereto at thefpivot thereof and a link pivoted to said last named member and the otherarm of said lever.

6. In va louver damper construction, the combination of a pair of pivoted louver blades, the

` edge of one blade overlapping the adjacent edge of said second blade, and a link pivoted to Asaid y of the other blade when said blades are in closed position, Va lever pivoted intermediate the ends thereof and intermediate the pivots of said blades, said lever comprising a pair of arms, one of said Varms being disposed at an angle of more than with respect to the other arm, the angle being measured intermediate the lever and said blades, a link pivoted to the rst named Varm and pivoted to one of the blades at a point spaced from the pivot of said blade and on the Vside of the pivot of said blade opposite to that on which said'lever pivoted, a member substantially perpendicular to the other blade and rigidly con- 

